#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>

int main()
{
    int a, b, c;
    while (~scanf("%d %d %d", &a, &b, &c)) {
        if (a + b > c && a + c > b && b + c > a) {
            if (a == b && a == c && b == c) printf("Equilateral triangle!\n");
            else if (a == b || a == c || b == c) printf("Isosceles triangle!\n");
            else printf("Ordinary triangle!\n");
        }
        else printf("Not a triangle!\n");
    }

    return 0;
}
//bc51